I ride my TorceForce ebike on 36V 10Amphour LiFePo from LifeBatt.
LifeBatt are not weak China brands cells, it uses Taiwan-made cells=quality.
Battery cost $750 and it was one of the best spend $750 in my life.
I know what are you going to say - soo expensive????
But it is not your duct tape,patched up, low C rate crap with faulty electronics sold on eBay.
I bougt and installed LifeBatt in June 2008 when odometer on my TF showed 10,500 km, now I got 20,100 km /yes that's over 10,000km ,I ride year round/
Numbers speak for themselves.
I charge LifeBatt twice/day sometimes 3 times a day and ride at minimum 333 days a year - that is say 700 charges a year, means this pack will be charged 2800 times in June 2012!!!
But it is not showing any signes of aging , voltage sags is exactely as it was,
couple of week ago I discharged to 9Ah and it was strong to the end of discharge.